Production of protein products by fermentation is a well know process and it is used for production in industrial scale of many different proteins of interest. During fermentation some of the host cells producing the protein product of interest will break and the content of the cells, including DNA, will be released to the fermentation broth. Furthermore, in some fermentation the protein of interest is produced as an intracellular product. This means that the cells must lyse as a part of the purification process following the fermentation and this inevitably results in the release of significant amounts of DNA into the fermentation broth.
For some types of protein products it is desired to avoid residual DNA from the host cells producing the protein of interest, e.g. due to environmental or health concerns. Furthermore, DNA in the fermentation broth may increase the viscosity leading to a higher energy demand for stirring and or handling the fermentation broth.
There is therefore a need for method for removing or reducing the DNA content of fermentation broth.
However, it is very difficult to remove all residual host cell DNA from a fermentation broth, so there is a desideratum in the art to develop procedures to overcome the DNA problem.